This invention relates to a mold for a semiconductor package and more particularly to a mold that may be used regardless of flange tip type. Consequently, the present mold can be used whether a flange tip supplies resin moving from above or below.
Generally, to manufacture a semiconductor, a mold for the semiconductor package molds resin compound on a lead frame which has been wire bonded and die bonded to protect the welding state of the lead frame and semiconductor chip.
Conventionally, a port (4) is located in the upper mold (1) and resin (3) is supplied into the port (4) and compressed with a flange tip (7) located completely out of the port as shown in FIG. 7.
A disadvantage of the prior art is that the flange tip (7) has a long stroke which reduces productivity. Furthermore, when the resin inserted into the port is compressed by the flange tip (7), since the air in the port goes through the semiconductor package together with resin, a plurality air-holes is often generated and/or a wire that connects a lead and a chip of semiconductor can easily be bent.
Furthermore, since resin (3) is inserted in space which is produced by a difference of temperature between the port (4) and the flange tip (7), abrasion is caused in the portion between the port (4) and the flange tip (7) and unsatisfactory operation of mold press may be produced which reduces reliability and increase expense.
A further form of a mold has been proposed. In this mold, resin (3) is fed while a flange tip (7) reciprocates upwards so that the upper space of the flange tip (7) in the port (4) may substantially equal to the volume of resin (3). Such a mold is entirely satisfactory in reducing the generation of air-holes and bending of wire. According to the present invention, productivity of the mold is increased owing to the short stroke and since the flange tip (7) is maintained at a predetermined temperature, thus a uniform gap between the port (4) and the flange tip (7), and increased durability of the pod and the flange tip (7) are realised. Consequently, this type of mold ensures the production of a precise semiconductor package.
However, as this type of mold press designed to cooperation with a flange tip that feeds resin into the mold with downward movement goes out of use commercially, productivity is not high enough compared with the number of mold press equipment.